1 /* $OpenBSD: misc.c,v 1.193 2024/04/02 10:02:08 deraadt Exp $ */ 2 /* 3 * Copyright (c) 2000 Markus Friedl. All rights reserved. 4 * Copyright (c) 2005-2020 Damien Miller. All rights reserved. 5 * Copyright (c) 2004 Henning Brauer <henning@openbsd.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 21 #include <sys/types.h> 22 #include <sys/ioctl.h> 23 #include <sys/socket.h> 24 #include <sys/stat.h> 25 #include <sys/time.h> 26 #include <sys/wait.h> 27 #include <sys/un.h> 28 29 #include <net/if.h> 30 #include <netinet/in.h> 31 #include <netinet/ip.h> 32 #include <netinet/tcp.h> 33 #include <arpa/inet.h> 34 35 #include <ctype.h> 36 #include <errno.h> 37 #include <fcntl.h> 38 #include <netdb.h> 39 #include <paths.h> 40 #include <pwd.h> 41 #include <libgen.h> 42 #include <limits.h> 43 #include <nlist.h> 44 #include <poll.h> 45 #include <signal.h> 46 #include <stdarg.h> 47 #include <stdio.h> 48 #include <stdint.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 53 #include "xmalloc.h" 54 #include "misc.h" 55 #include "log.h" 56 #include "ssh.h" 57 #include "sshbuf.h" 58 #include "ssherr.h" 59 60 /* remove newline at end of string */ 61 char * 62 chop(char *s) 63 { 64 char *t = s; 65 while (*t) { 66 if (*t == '\n' || *t == '\r') { 67 *t = '\0'; 68 return s; 69 } 70 t++; 71 } 72 return s; 73 74 } 75 76 /* remove whitespace from end of string */ 77 void 78 rtrim(char *s) 79 { 80 size_t i; 81 82 if ((i = strlen(s)) == 0) 83 return; 84 for (i--; i > 0; i--) { 85 if (isspace((unsigned char)s[i])) 86 s[i] = '\0'; 87 } 88 } 89 90 /* set/unset filedescriptor to non-blocking */ 91 int 92 set_nonblock(int fd) 93 { 94 int val; 95 96 val = fcntl(fd, F_GETFL); 97 if (val == -1) { 98 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 99 return (-1); 100 } 101 if (val & O_NONBLOCK) { 102 debug3("fd %d is O_NONBLOCK", fd); 103 return (0); 104 } 105 debug2("fd %d setting O_NONBLOCK", fd); 106 val |= O_NONBLOCK; 107 if (fcntl(fd, F_SETFL, val) == -1) { 108 debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, 109 strerror(errno)); 110 return (-1); 111 } 112 return (0); 113 } 114 115 int 116 unset_nonblock(int fd) 117 { 118 int val; 119 120 val = fcntl(fd, F_GETFL); 121 if (val == -1) { 122 error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); 123 return (-1); 124 } 125 if (!(val & O_NONBLOCK)) { 126 debug3("fd %d is not O_NONBLOCK", fd); 127 return (0); 128 } 129 debug("fd %d clearing O_NONBLOCK", fd); 130 val &= ~O_NONBLOCK; 131 if (fcntl(fd, F_SETFL, val) == -1) { 132 debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", 133 fd, strerror(errno)); 134 return (-1); 135 } 136 return (0); 137 } 138 139 const char * 140 ssh_gai_strerror(int gaierr) 141 { 142 if (gaierr == EAI_SYSTEM && errno != 0) 143 return strerror(errno); 144 return gai_strerror(gaierr); 145 } 146 147 /* disable nagle on socket */ 148 void 149 set_nodelay(int fd) 150 { 151 int opt; 152 socklen_t optlen; 153 154 optlen = sizeof opt; 155 if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { 156 debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); 157 return; 158 } 159 if (opt == 1) { 160 debug2("fd %d is TCP_NODELAY", fd); 161 return; 162 } 163 opt = 1; 164 debug2("fd %d setting TCP_NODELAY", fd); 165 if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) 166 error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); 167 } 168 169 /* Allow local port reuse in TIME_WAIT */ 170 int 171 set_reuseaddr(int fd) 172 { 173 int on = 1; 174 175 if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { 176 error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); 177 return -1; 178 } 179 return 0; 180 } 181 182 /* Get/set routing domain */ 183 char * 184 get_rdomain(int fd) 185 { 186 int rtable; 187 char *ret; 188 socklen_t len = sizeof(rtable); 189 190 if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { 191 error("Failed to get routing domain for fd %d: %s", 192 fd, strerror(errno)); 193 return NULL; 194 } 195 xasprintf(&ret, "%d", rtable); 196 return ret; 197 } 198 199 int 200 set_rdomain(int fd, const char *name) 201 { 202 int rtable; 203 const char *errstr; 204 205 if (name == NULL) 206 return 0; /* default table */ 207 208 rtable = (int)strtonum(name, 0, 255, &errstr); 209 if (errstr != NULL) { 210 /* Shouldn't happen */ 211 error("Invalid routing domain \"%s\": %s", name, errstr); 212 return -1; 213 } 214 if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, 215 &rtable, sizeof(rtable)) == -1) { 216 error("Failed to set routing domain %d on fd %d: %s", 217 rtable, fd, strerror(errno)); 218 return -1; 219 } 220 return 0; 221 } 222 223 int 224 get_sock_af(int fd) 225 { 226 struct sockaddr_storage to; 227 socklen_t tolen = sizeof(to); 228 229 memset(&to, 0, sizeof(to)); 230 if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) 231 return -1; 232 return to.ss_family; 233 } 234 235 void 236 set_sock_tos(int fd, int tos) 237 { 238 int af; 239 240 switch ((af = get_sock_af(fd))) { 241 case -1: 242 /* assume not a socket */ 243 break; 244 case AF_INET: 245 debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); 246 if (setsockopt(fd, IPPROTO_IP, IP_TOS, 247 &tos, sizeof(tos)) == -1) { 248 error("setsockopt socket %d IP_TOS %d: %s", 249 fd, tos, strerror(errno)); 250 } 251 break; 252 case AF_INET6: 253 debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); 254 if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, 255 &tos, sizeof(tos)) == -1) { 256 error("setsockopt socket %d IPV6_TCLASS %d: %s", 257 fd, tos, strerror(errno)); 258 } 259 break; 260 default: 261 debug2_f("unsupported socket family %d", af); 262 break; 263 } 264 } 265 266 /* 267 * Wait up to *timeoutp milliseconds for events on fd. Updates 268 * *timeoutp with time remaining. 269 * Returns 0 if fd ready or -1 on timeout or error (see errno). 270 */ 271 static int 272 waitfd(int fd, int *timeoutp, short events, volatile sig_atomic_t *stop) 273 { 274 struct pollfd pfd; 275 struct timespec timeout; 276 int oerrno, r; 277 sigset_t nsigset, osigset; 278 279 if (timeoutp && *timeoutp == -1) 280 timeoutp = NULL; 281 pfd.fd = fd; 282 pfd.events = events; 283 ptimeout_init(&timeout); 284 if (timeoutp != NULL) 285 ptimeout_deadline_ms(&timeout, *timeoutp); 286 if (stop != NULL) 287 sigfillset(&nsigset); 288 for (; timeoutp == NULL || *timeoutp >= 0;) { 289 if (stop != NULL) { 290 sigprocmask(SIG_BLOCK, &nsigset, &osigset); 291 if (*stop) { 292 sigprocmask(SIG_SETMASK, &osigset, NULL); 293 errno = EINTR; 294 return -1; 295 } 296 } 297 r = ppoll(&pfd, 1, ptimeout_get_tsp(&timeout), 298 stop != NULL ? &osigset : NULL); 299 oerrno = errno; 300 if (stop != NULL) 301 sigprocmask(SIG_SETMASK, &osigset, NULL); 302 if (timeoutp) 303 *timeoutp = ptimeout_get_ms(&timeout); 304 errno = oerrno; 305 if (r > 0) 306 return 0; 307 else if (r == -1 && errno != EAGAIN && errno != EINTR) 308 return -1; 309 else if (r == 0) 310 break; 311 } 312 /* timeout */ 313 errno = ETIMEDOUT; 314 return -1; 315 } 316 317 /* 318 * Wait up to *timeoutp milliseconds for fd to be readable. Updates 319 * *timeoutp with time remaining. 320 * Returns 0 if fd ready or -1 on timeout or error (see errno). 321 */ 322 int 323 waitrfd(int fd, int *timeoutp, volatile sig_atomic_t *stop) { 324 return waitfd(fd, timeoutp, POLLIN, stop); 325 } 326 327 /* 328 * Attempt a non-blocking connect(2) to the specified address, waiting up to 329 * *timeoutp milliseconds for the connection to complete. If the timeout is 330 * <=0, then wait indefinitely. 331 * 332 * Returns 0 on success or -1 on failure. 333 */ 334 int 335 timeout_connect(int sockfd, const struct sockaddr *serv_addr, 336 socklen_t addrlen, int *timeoutp) 337 { 338 int optval = 0; 339 socklen_t optlen = sizeof(optval); 340 341 /* No timeout: just do a blocking connect() */ 342 if (timeoutp == NULL || *timeoutp <= 0) 343 return connect(sockfd, serv_addr, addrlen); 344 345 set_nonblock(sockfd); 346 for (;;) { 347 if (connect(sockfd, serv_addr, addrlen) == 0) { 348 /* Succeeded already? */ 349 unset_nonblock(sockfd); 350 return 0; 351 } else if (errno == EINTR) 352 continue; 353 else if (errno != EINPROGRESS) 354 return -1; 355 break; 356 } 357 358 if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT, NULL) == -1) 359 return -1; 360 361 /* Completed or failed */ 362 if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { 363 debug("getsockopt: %s", strerror(errno)); 364 return -1; 365 } 366 if (optval != 0) { 367 errno = optval; 368 return -1; 369 } 370 unset_nonblock(sockfd); 371 return 0; 372 } 373 374 /* Characters considered whitespace in strsep calls. */ 375 #define WHITESPACE " \t\r\n" 376 #define QUOTE "\"" 377 378 /* return next token in configuration line */ 379 static char * 380 strdelim_internal(char **s, int split_equals) 381 { 382 char *old; 383 int wspace = 0; 384 385 if (*s == NULL) 386 return NULL; 387 388 old = *s; 389 390 *s = strpbrk(*s, 391 split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); 392 if (*s == NULL) 393 return (old); 394 395 if (*s[0] == '\"') { 396 memmove(*s, *s + 1, strlen(*s)); /* move nul too */ 397 /* Find matching quote */ 398 if ((*s = strpbrk(*s, QUOTE)) == NULL) { 399 return (NULL); /* no matching quote */ 400 } else { 401 *s[0] = '\0'; 402 *s += strspn(*s + 1, WHITESPACE) + 1; 403 return (old); 404 } 405 } 406 407 /* Allow only one '=' to be skipped */ 408 if (split_equals && *s[0] == '=') 409 wspace = 1; 410 *s[0] = '\0'; 411 412 /* Skip any extra whitespace after first token */ 413 *s += strspn(*s + 1, WHITESPACE) + 1; 414 if (split_equals && *s[0] == '=' && !wspace) 415 *s += strspn(*s + 1, WHITESPACE) + 1; 416 417 return (old); 418 } 419 420 /* 421 * Return next token in configuration line; splts on whitespace or a 422 * single '=' character. 423 */ 424 char * 425 strdelim(char **s) 426 { 427 return strdelim_internal(s, 1); 428 } 429 430 /* 431 * Return next token in configuration line; splts on whitespace only. 432 */ 433 char * 434 strdelimw(char **s) 435 { 436 return strdelim_internal(s, 0); 437 } 438 439 struct passwd * 440 pwcopy(struct passwd *pw) 441 { 442 struct passwd *copy = xcalloc(1, sizeof(*copy)); 443 444 copy->pw_name = xstrdup(pw->pw_name); 445 copy->pw_passwd = xstrdup(pw->pw_passwd); 446 copy->pw_gecos = xstrdup(pw->pw_gecos); 447 copy->pw_uid = pw->pw_uid; 448 copy->pw_gid = pw->pw_gid; 449 copy->pw_expire = pw->pw_expire; 450 copy->pw_change = pw->pw_change; 451 copy->pw_class = xstrdup(pw->pw_class); 452 copy->pw_dir = xstrdup(pw->pw_dir); 453 copy->pw_shell = xstrdup(pw->pw_shell); 454 return copy; 455 } 456 457 /* 458 * Convert ASCII string to TCP/IP port number. 459 * Port must be >=0 and <=65535. 460 * Return -1 if invalid. 461 */ 462 int 463 a2port(const char *s) 464 { 465 struct servent *se; 466 long long port; 467 const char *errstr; 468 469 port = strtonum(s, 0, 65535, &errstr); 470 if (errstr == NULL) 471 return (int)port; 472 if ((se = getservbyname(s, "tcp")) != NULL) 473 return ntohs(se->s_port); 474 return -1; 475 } 476 477 int 478 a2tun(const char *s, int *remote) 479 { 480 const char *errstr = NULL; 481 char *sp, *ep; 482 int tun; 483 484 if (remote != NULL) { 485 *remote = SSH_TUNID_ANY; 486 sp = xstrdup(s); 487 if ((ep = strchr(sp, ':')) == NULL) { 488 free(sp); 489 return (a2tun(s, NULL)); 490 } 491 ep[0] = '\0'; ep++; 492 *remote = a2tun(ep, NULL); 493 tun = a2tun(sp, NULL); 494 free(sp); 495 return (*remote == SSH_TUNID_ERR ? *remote : tun); 496 } 497 498 if (strcasecmp(s, "any") == 0) 499 return (SSH_TUNID_ANY); 500 501 tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); 502 if (errstr != NULL) 503 return (SSH_TUNID_ERR); 504 505 return (tun); 506 } 507 508 #define SECONDS 1 509 #define MINUTES (SECONDS * 60) 510 #define HOURS (MINUTES * 60) 511 #define DAYS (HOURS * 24) 512 #define WEEKS (DAYS * 7) 513 514 static char * 515 scandigits(char *s) 516 { 517 while (isdigit((unsigned char)*s)) 518 s++; 519 return s; 520 } 521 522 /* 523 * Convert a time string into seconds; format is 524 * a sequence of: 525 * time[qualifier] 526 * 527 * Valid time qualifiers are: 528 * <none> seconds 529 * s|S seconds 530 * m|M minutes 531 * h|H hours 532 * d|D days 533 * w|W weeks 534 * 535 * Examples: 536 * 90m 90 minutes 537 * 1h30m 90 minutes 538 * 2d 2 days 539 * 1w 1 week 540 * 541 * Return -1 if time string is invalid. 542 */ 543 int 544 convtime(const char *s) 545 { 546 int secs, total = 0, multiplier; 547 char *p, *os, *np, c; 548 const char *errstr; 549 550 if (s == NULL || *s == '\0') 551 return -1; 552 p = os = strdup(s); /* deal with const */ 553 if (os == NULL) 554 return -1; 555 556 while (*p) { 557 np = scandigits(p); 558 if (np) { 559 c = *np; 560 *np = '\0'; 561 } 562 secs = (int)strtonum(p, 0, INT_MAX, &errstr); 563 if (errstr) 564 goto fail; 565 *np = c; 566 567 multiplier = 1; 568 switch (c) { 569 case '\0': 570 np--; /* back up */ 571 break; 572 case 's': 573 case 'S': 574 break; 575 case 'm': 576 case 'M': 577 multiplier = MINUTES; 578 break; 579 case 'h': 580 case 'H': 581 multiplier = HOURS; 582 break; 583 case 'd': 584 case 'D': 585 multiplier = DAYS; 586 break; 587 case 'w': 588 case 'W': 589 multiplier = WEEKS; 590 break; 591 default: 592 goto fail; 593 } 594 if (secs > INT_MAX / multiplier) 595 goto fail; 596 secs *= multiplier; 597 if (total > INT_MAX - secs) 598 goto fail; 599 total += secs; 600 if (total < 0) 601 goto fail; 602 p = ++np; 603 } 604 free(os); 605 return total; 606 fail: 607 free(os); 608 return -1; 609 } 610 611 #define TF_BUFS 8 612 #define TF_LEN 9 613 614 const char * 615 fmt_timeframe(time_t t) 616 { 617 char *buf; 618 static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ 619 static int idx = 0; 620 unsigned int sec, min, hrs, day; 621 unsigned long long week; 622 623 buf = tfbuf[idx++]; 624 if (idx == TF_BUFS) 625 idx = 0; 626 627 week = t; 628 629 sec = week % 60; 630 week /= 60; 631 min = week % 60; 632 week /= 60; 633 hrs = week % 24; 634 week /= 24; 635 day = week % 7; 636 week /= 7; 637 638 if (week > 0) 639 snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); 640 else if (day > 0) 641 snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); 642 else 643 snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); 644 645 return (buf); 646 } 647 648 /* 649 * Returns a standardized host+port identifier string. 650 * Caller must free returned string. 651 */ 652 char * 653 put_host_port(const char *host, u_short port) 654 { 655 char *hoststr; 656 657 if (port == 0 || port == SSH_DEFAULT_PORT) 658 return(xstrdup(host)); 659 if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) 660 fatal("put_host_port: asprintf: %s", strerror(errno)); 661 debug3("put_host_port: %s", hoststr); 662 return hoststr; 663 } 664 665 /* 666 * Search for next delimiter between hostnames/addresses and ports. 667 * Argument may be modified (for termination). 668 * Returns *cp if parsing succeeds. 669 * *cp is set to the start of the next field, if one was found. 670 * The delimiter char, if present, is stored in delim. 671 * If this is the last field, *cp is set to NULL. 672 */ 673 char * 674 hpdelim2(char **cp, char *delim) 675 { 676 char *s, *old; 677 678 if (cp == NULL || *cp == NULL) 679 return NULL; 680 681 old = s = *cp; 682 if (*s == '[') { 683 if ((s = strchr(s, ']')) == NULL) 684 return NULL; 685 else 686 s++; 687 } else if ((s = strpbrk(s, ":/")) == NULL) 688 s = *cp + strlen(*cp); /* skip to end (see first case below) */ 689 690 switch (*s) { 691 case '\0': 692 *cp = NULL; /* no more fields*/ 693 break; 694 695 case ':': 696 case '/': 697 if (delim != NULL) 698 *delim = *s; 699 *s = '\0'; /* terminate */ 700 *cp = s + 1; 701 break; 702 703 default: 704 return NULL; 705 } 706 707 return old; 708 } 709 710 /* The common case: only accept colon as delimiter. */ 711 char * 712 hpdelim(char **cp) 713 { 714 char *r, delim = '\0'; 715 716 r = hpdelim2(cp, &delim); 717 if (delim == '/') 718 return NULL; 719 return r; 720 } 721 722 char * 723 cleanhostname(char *host) 724 { 725 if (*host == '[' && host[strlen(host) - 1] == ']') { 726 host[strlen(host) - 1] = '\0'; 727 return (host + 1); 728 } else 729 return host; 730 } 731 732 char * 733 colon(char *cp) 734 { 735 int flag = 0; 736 737 if (*cp == ':') /* Leading colon is part of file name. */ 738 return NULL; 739 if (*cp == '[') 740 flag = 1; 741 742 for (; *cp; ++cp) { 743 if (*cp == '@' && *(cp+1) == '[') 744 flag = 1; 745 if (*cp == ']' && *(cp+1) == ':' && flag) 746 return (cp+1); 747 if (*cp == ':' && !flag) 748 return (cp); 749 if (*cp == '/') 750 return NULL; 751 } 752 return NULL; 753 } 754 755 /* 756 * Parse a [user@]host:[path] string. 757 * Caller must free returned user, host and path. 758 * Any of the pointer return arguments may be NULL (useful for syntax checking). 759 * If user was not specified then *userp will be set to NULL. 760 * If host was not specified then *hostp will be set to NULL. 761 * If path was not specified then *pathp will be set to ".". 762 * Returns 0 on success, -1 on failure. 763 */ 764 int 765 parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) 766 { 767 char *user = NULL, *host = NULL, *path = NULL; 768 char *sdup, *tmp; 769 int ret = -1; 770 771 if (userp != NULL) 772 *userp = NULL; 773 if (hostp != NULL) 774 *hostp = NULL; 775 if (pathp != NULL) 776 *pathp = NULL; 777 778 sdup = xstrdup(s); 779 780 /* Check for remote syntax: [user@]host:[path] */ 781 if ((tmp = colon(sdup)) == NULL) 782 goto out; 783 784 /* Extract optional path */ 785 *tmp++ = '\0'; 786 if (*tmp == '\0') 787 tmp = "."; 788 path = xstrdup(tmp); 789 790 /* Extract optional user and mandatory host */ 791 tmp = strrchr(sdup, '@'); 792 if (tmp != NULL) { 793 *tmp++ = '\0'; 794 host = xstrdup(cleanhostname(tmp)); 795 if (*sdup != '\0') 796 user = xstrdup(sdup); 797 } else { 798 host = xstrdup(cleanhostname(sdup)); 799 user = NULL; 800 } 801 802 /* Success */ 803 if (userp != NULL) { 804 *userp = user; 805 user = NULL; 806 } 807 if (hostp != NULL) { 808 *hostp = host; 809 host = NULL; 810 } 811 if (pathp != NULL) { 812 *pathp = path; 813 path = NULL; 814 } 815 ret = 0; 816 out: 817 free(sdup); 818 free(user); 819 free(host); 820 free(path); 821 return ret; 822 } 823 824 /* 825 * Parse a [user@]host[:port] string. 826 * Caller must free returned user and host. 827 * Any of the pointer return arguments may be NULL (useful for syntax checking). 828 * If user was not specified then *userp will be set to NULL. 829 * If port was not specified then *portp will be -1. 830 * Returns 0 on success, -1 on failure. 831 */ 832 int 833 parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) 834 { 835 char *sdup, *cp, *tmp; 836 char *user = NULL, *host = NULL; 837 int port = -1, ret = -1; 838 839 if (userp != NULL) 840 *userp = NULL; 841 if (hostp != NULL) 842 *hostp = NULL; 843 if (portp != NULL) 844 *portp = -1; 845 846 if ((sdup = tmp = strdup(s)) == NULL) 847 return -1; 848 /* Extract optional username */ 849 if ((cp = strrchr(tmp, '@')) != NULL) { 850 *cp = '\0'; 851 if (*tmp == '\0') 852 goto out; 853 if ((user = strdup(tmp)) == NULL) 854 goto out; 855 tmp = cp + 1; 856 } 857 /* Extract mandatory hostname */ 858 if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') 859 goto out; 860 host = xstrdup(cleanhostname(cp)); 861 /* Convert and verify optional port */ 862 if (tmp != NULL && *tmp != '\0') { 863 if ((port = a2port(tmp)) <= 0) 864 goto out; 865 } 866 /* Success */ 867 if (userp != NULL) { 868 *userp = user; 869 user = NULL; 870 } 871 if (hostp != NULL) { 872 *hostp = host; 873 host = NULL; 874 } 875 if (portp != NULL) 876 *portp = port; 877 ret = 0; 878 out: 879 free(sdup); 880 free(user); 881 free(host); 882 return ret; 883 } 884 885 /* 886 * Converts a two-byte hex string to decimal. 887 * Returns the decimal value or -1 for invalid input. 888 */ 889 static int 890 hexchar(const char *s) 891 { 892 unsigned char result[2]; 893 int i; 894 895 for (i = 0; i < 2; i++) { 896 if (s[i] >= '0' && s[i] <= '9') 897 result[i] = (unsigned char)(s[i] - '0'); 898 else if (s[i] >= 'a' && s[i] <= 'f') 899 result[i] = (unsigned char)(s[i] - 'a') + 10; 900 else if (s[i] >= 'A' && s[i] <= 'F') 901 result[i] = (unsigned char)(s[i] - 'A') + 10; 902 else 903 return -1; 904 } 905 return (result[0] << 4) | result[1]; 906 } 907 908 /* 909 * Decode an url-encoded string. 910 * Returns a newly allocated string on success or NULL on failure. 911 */ 912 static char * 913 urldecode(const char *src) 914 { 915 char *ret, *dst; 916 int ch; 917 size_t srclen; 918 919 if ((srclen = strlen(src)) >= SIZE_MAX) 920 fatal_f("input too large"); 921 ret = xmalloc(srclen + 1); 922 for (dst = ret; *src != '\0'; src++) { 923 switch (*src) { 924 case '+': 925 *dst++ = ' '; 926 break; 927 case '%': 928 if (!isxdigit((unsigned char)src[1]) || 929 !isxdigit((unsigned char)src[2]) || 930 (ch = hexchar(src + 1)) == -1) { 931 free(ret); 932 return NULL; 933 } 934 *dst++ = ch; 935 src += 2; 936 break; 937 default: 938 *dst++ = *src; 939 break; 940 } 941 } 942 *dst = '\0'; 943 944 return ret; 945 } 946 947 /* 948 * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. 949 * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 950 * Either user or path may be url-encoded (but not host or port). 951 * Caller must free returned user, host and path. 952 * Any of the pointer return arguments may be NULL (useful for syntax checking) 953 * but the scheme must always be specified. 954 * If user was not specified then *userp will be set to NULL. 955 * If port was not specified then *portp will be -1. 956 * If path was not specified then *pathp will be set to NULL. 957 * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. 958 */ 959 int 960 parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, 961 int *portp, char **pathp) 962 { 963 char *uridup, *cp, *tmp, ch; 964 char *user = NULL, *host = NULL, *path = NULL; 965 int port = -1, ret = -1; 966 size_t len; 967 968 len = strlen(scheme); 969 if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) 970 return 1; 971 uri += len + 3; 972 973 if (userp != NULL) 974 *userp = NULL; 975 if (hostp != NULL) 976 *hostp = NULL; 977 if (portp != NULL) 978 *portp = -1; 979 if (pathp != NULL) 980 *pathp = NULL; 981 982 uridup = tmp = xstrdup(uri); 983 984 /* Extract optional ssh-info (username + connection params) */ 985 if ((cp = strchr(tmp, '@')) != NULL) { 986 char *delim; 987 988 *cp = '\0'; 989 /* Extract username and connection params */ 990 if ((delim = strchr(tmp, ';')) != NULL) { 991 /* Just ignore connection params for now */ 992 *delim = '\0'; 993 } 994 if (*tmp == '\0') { 995 /* Empty username */ 996 goto out; 997 } 998 if ((user = urldecode(tmp)) == NULL) 999 goto out; 1000 tmp = cp + 1; 1001 } 1002 1003 /* Extract mandatory hostname */ 1004 if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') 1005 goto out; 1006 host = xstrdup(cleanhostname(cp)); 1007 if (!valid_domain(host, 0, NULL)) 1008 goto out; 1009 1010 if (tmp != NULL && *tmp != '\0') { 1011 if (ch == ':') { 1012 /* Convert and verify port. */ 1013 if ((cp = strchr(tmp, '/')) != NULL) 1014 *cp = '\0'; 1015 if ((port = a2port(tmp)) <= 0) 1016 goto out; 1017 tmp = cp ? cp + 1 : NULL; 1018 } 1019 if (tmp != NULL && *tmp != '\0') { 1020 /* Extract optional path */ 1021 if ((path = urldecode(tmp)) == NULL) 1022 goto out; 1023 } 1024 } 1025 1026 /* Success */ 1027 if (userp != NULL) { 1028 *userp = user; 1029 user = NULL; 1030 } 1031 if (hostp != NULL) { 1032 *hostp = host; 1033 host = NULL; 1034 } 1035 if (portp != NULL) 1036 *portp = port; 1037 if (pathp != NULL) { 1038 *pathp = path; 1039 path = NULL; 1040 } 1041 ret = 0; 1042 out: 1043 free(uridup); 1044 free(user); 1045 free(host); 1046 free(path); 1047 return ret; 1048 } 1049 1050 /* function to assist building execv() arguments */ 1051 void 1052 addargs(arglist *args, char *fmt, ...) 1053 { 1054 va_list ap; 1055 char *cp; 1056 u_int nalloc; 1057 int r; 1058 1059 va_start(ap, fmt); 1060 r = vasprintf(&cp, fmt, ap); 1061 va_end(ap); 1062 if (r == -1) 1063 fatal_f("argument too long"); 1064 1065 nalloc = args->nalloc; 1066 if (args->list == NULL) { 1067 nalloc = 32; 1068 args->num = 0; 1069 } else if (args->num > (256 * 1024)) 1070 fatal_f("too many arguments"); 1071 else if (args->num >= args->nalloc) 1072 fatal_f("arglist corrupt"); 1073 else if (args->num+2 >= nalloc) 1074 nalloc *= 2; 1075 1076 args->list = xrecallocarray(args->list, args->nalloc, 1077 nalloc, sizeof(char *)); 1078 args->nalloc = nalloc; 1079 args->list[args->num++] = cp; 1080 args->list[args->num] = NULL; 1081 } 1082 1083 void 1084 replacearg(arglist *args, u_int which, char *fmt, ...) 1085 { 1086 va_list ap; 1087 char *cp; 1088 int r; 1089 1090 va_start(ap, fmt); 1091 r = vasprintf(&cp, fmt, ap); 1092 va_end(ap); 1093 if (r == -1) 1094 fatal_f("argument too long"); 1095 if (args->list == NULL || args->num >= args->nalloc) 1096 fatal_f("arglist corrupt"); 1097 1098 if (which >= args->num) 1099 fatal_f("tried to replace invalid arg %d >= %d", 1100 which, args->num); 1101 free(args->list[which]); 1102 args->list[which] = cp; 1103 } 1104 1105 void 1106 freeargs(arglist *args) 1107 { 1108 u_int i; 1109 1110 if (args == NULL) 1111 return; 1112 if (args->list != NULL && args->num < args->nalloc) { 1113 for (i = 0; i < args->num; i++) 1114 free(args->list[i]); 1115 free(args->list); 1116 } 1117 args->nalloc = args->num = 0; 1118 args->list = NULL; 1119 } 1120 1121 /* 1122 * Expands tildes in the file name. Returns data allocated by xmalloc. 1123 * Warning: this calls getpw*. 1124 */ 1125 int 1126 tilde_expand(const char *filename, uid_t uid, char **retp) 1127 { 1128 char *ocopy = NULL, *copy, *s = NULL; 1129 const char *path = NULL, *user = NULL; 1130 struct passwd *pw; 1131 size_t len; 1132 int ret = -1, r, slash; 1133 1134 *retp = NULL; 1135 if (*filename != '~') { 1136 *retp = xstrdup(filename); 1137 return 0; 1138 } 1139 ocopy = copy = xstrdup(filename + 1); 1140 1141 if (*copy == '\0') /* ~ */ 1142 path = NULL; 1143 else if (*copy == '/') { 1144 copy += strspn(copy, "/"); 1145 if (*copy == '\0') 1146 path = NULL; /* ~/ */ 1147 else 1148 path = copy; /* ~/path */ 1149 } else { 1150 user = copy; 1151 if ((path = strchr(copy, '/')) != NULL) { 1152 copy[path - copy] = '\0'; 1153 path++; 1154 path += strspn(path, "/"); 1155 if (*path == '\0') /* ~user/ */ 1156 path = NULL; 1157 /* else ~user/path */ 1158 } 1159 /* else ~user */ 1160 } 1161 if (user != NULL) { 1162 if ((pw = getpwnam(user)) == NULL) { 1163 error_f("No such user %s", user); 1164 goto out; 1165 } 1166 } else if ((pw = getpwuid(uid)) == NULL) { 1167 error_f("No such uid %ld", (long)uid); 1168 goto out; 1169 } 1170 1171 /* Make sure directory has a trailing '/' */ 1172 slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/'; 1173 1174 if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir, 1175 slash ? "/" : "", path != NULL ? path : "")) <= 0) { 1176 error_f("xasprintf failed"); 1177 goto out; 1178 } 1179 if (r >= PATH_MAX) { 1180 error_f("Path too long"); 1181 goto out; 1182 } 1183 /* success */ 1184 ret = 0; 1185 *retp = s; 1186 s = NULL; 1187 out: 1188 free(s); 1189 free(ocopy); 1190 return ret; 1191 } 1192 1193 char * 1194 tilde_expand_filename(const char *filename, uid_t uid) 1195 { 1196 char *ret; 1197 1198 if (tilde_expand(filename, uid, &ret) != 0) 1199 cleanup_exit(255); 1200 return ret; 1201 } 1202 1203 /* 1204 * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} 1205 * substitutions. A number of escapes may be specified as 1206 * (char *escape_chars, char *replacement) pairs. The list must be terminated 1207 * by a NULL escape_char. Returns replaced string in memory allocated by 1208 * xmalloc which the caller must free. 1209 */ 1210 static char * 1211 vdollar_percent_expand(int *parseerror, int dollar, int percent, 1212 const char *string, va_list ap) 1213 { 1214 #define EXPAND_MAX_KEYS 64 1215 u_int num_keys = 0, i; 1216 struct { 1217 const char *key; 1218 const char *repl; 1219 } keys[EXPAND_MAX_KEYS]; 1220 struct sshbuf *buf; 1221 int r, missingvar = 0; 1222 char *ret = NULL, *var, *varend, *val; 1223 size_t len; 1224 1225 if ((buf = sshbuf_new()) == NULL) 1226 fatal_f("sshbuf_new failed"); 1227 if (parseerror == NULL) 1228 fatal_f("null parseerror arg"); 1229 *parseerror = 1; 1230 1231 /* Gather keys if we're doing percent expansion. */ 1232 if (percent) { 1233 for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { 1234 keys[num_keys].key = va_arg(ap, char *); 1235 if (keys[num_keys].key == NULL) 1236 break; 1237 keys[num_keys].repl = va_arg(ap, char *); 1238 if (keys[num_keys].repl == NULL) { 1239 fatal_f("NULL replacement for token %s", 1240 keys[num_keys].key); 1241 } 1242 } 1243 if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) 1244 fatal_f("too many keys"); 1245 if (num_keys == 0) 1246 fatal_f("percent expansion without token list"); 1247 } 1248 1249 /* Expand string */ 1250 for (i = 0; *string != '\0'; string++) { 1251 /* Optionally process ${ENVIRONMENT} expansions. */ 1252 if (dollar && string[0] == '$' && string[1] == '{') { 1253 string += 2; /* skip over '${' */ 1254 if ((varend = strchr(string, '}')) == NULL) { 1255 error_f("environment variable '%s' missing " 1256 "closing '}'", string); 1257 goto out; 1258 } 1259 len = varend - string; 1260 if (len == 0) { 1261 error_f("zero-length environment variable"); 1262 goto out; 1263 } 1264 var = xmalloc(len + 1); 1265 (void)strlcpy(var, string, len + 1); 1266 if ((val = getenv(var)) == NULL) { 1267 error_f("env var ${%s} has no value", var); 1268 missingvar = 1; 1269 } else { 1270 debug3_f("expand ${%s} -> '%s'", var, val); 1271 if ((r = sshbuf_put(buf, val, strlen(val))) !=0) 1272 fatal_fr(r, "sshbuf_put ${}"); 1273 } 1274 free(var); 1275 string += len; 1276 continue; 1277 } 1278 1279 /* 1280 * Process percent expansions if we have a list of TOKENs. 1281 * If we're not doing percent expansion everything just gets 1282 * appended here. 1283 */ 1284 if (*string != '%' || !percent) { 1285 append: 1286 if ((r = sshbuf_put_u8(buf, *string)) != 0) 1287 fatal_fr(r, "sshbuf_put_u8 %%"); 1288 continue; 1289 } 1290 string++; 1291 /* %% case */ 1292 if (*string == '%') 1293 goto append; 1294 if (*string == '\0') { 1295 error_f("invalid format"); 1296 goto out; 1297 } 1298 for (i = 0; i < num_keys; i++) { 1299 if (strchr(keys[i].key, *string) != NULL) { 1300 if ((r = sshbuf_put(buf, keys[i].repl, 1301 strlen(keys[i].repl))) != 0) 1302 fatal_fr(r, "sshbuf_put %%-repl"); 1303 break; 1304 } 1305 } 1306 if (i >= num_keys) { 1307 error_f("unknown key %%%c", *string); 1308 goto out; 1309 } 1310 } 1311 if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) 1312 fatal_f("sshbuf_dup_string failed"); 1313 *parseerror = 0; 1314 out: 1315 sshbuf_free(buf); 1316 return *parseerror ? NULL : ret; 1317 #undef EXPAND_MAX_KEYS 1318 } 1319 1320 /* 1321 * Expand only environment variables. 1322 * Note that although this function is variadic like the other similar 1323 * functions, any such arguments will be unused. 1324 */ 1325 1326 char * 1327 dollar_expand(int *parseerr, const char *string, ...) 1328 { 1329 char *ret; 1330 int err; 1331 va_list ap; 1332 1333 va_start(ap, string); 1334 ret = vdollar_percent_expand(&err, 1, 0, string, ap); 1335 va_end(ap); 1336 if (parseerr != NULL) 1337 *parseerr = err; 1338 return ret; 1339 } 1340 1341 /* 1342 * Returns expanded string or NULL if a specified environment variable is 1343 * not defined, or calls fatal if the string is invalid. 1344 */ 1345 char * 1346 percent_expand(const char *string, ...) 1347 { 1348 char *ret; 1349 int err; 1350 va_list ap; 1351 1352 va_start(ap, string); 1353 ret = vdollar_percent_expand(&err, 0, 1, string, ap); 1354 va_end(ap); 1355 if (err) 1356 fatal_f("failed"); 1357 return ret; 1358 } 1359 1360 /* 1361 * Returns expanded string or NULL if a specified environment variable is 1362 * not defined, or calls fatal if the string is invalid. 1363 */ 1364 char * 1365 percent_dollar_expand(const char *string, ...) 1366 { 1367 char *ret; 1368 int err; 1369 va_list ap; 1370 1371 va_start(ap, string); 1372 ret = vdollar_percent_expand(&err, 1, 1, string, ap); 1373 va_end(ap); 1374 if (err) 1375 fatal_f("failed"); 1376 return ret; 1377 } 1378 1379 int 1380 tun_open(int tun, int mode, char **ifname) 1381 { 1382 struct ifreq ifr; 1383 char name[100]; 1384 int fd = -1, sock; 1385 const char *tunbase = "tun"; 1386 1387 if (ifname != NULL) 1388 *ifname = NULL; 1389 1390 if (mode == SSH_TUNMODE_ETHERNET) 1391 tunbase = "tap"; 1392 1393 /* Open the tunnel device */ 1394 if (tun <= SSH_TUNID_MAX) { 1395 snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); 1396 fd = open(name, O_RDWR); 1397 } else if (tun == SSH_TUNID_ANY) { 1398 for (tun = 100; tun >= 0; tun--) { 1399 snprintf(name, sizeof(name), "/dev/%s%d", 1400 tunbase, tun); 1401 if ((fd = open(name, O_RDWR)) >= 0) 1402 break; 1403 } 1404 } else { 1405 debug_f("invalid tunnel %u", tun); 1406 return -1; 1407 } 1408 1409 if (fd == -1) { 1410 debug_f("%s open: %s", name, strerror(errno)); 1411 return -1; 1412 } 1413 1414 debug_f("%s mode %d fd %d", name, mode, fd); 1415 1416 /* Bring interface up if it is not already */ 1417 snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); 1418 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) 1419 goto failed; 1420 1421 if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { 1422 debug_f("get interface %s flags: %s", ifr.ifr_name, 1423 strerror(errno)); 1424 goto failed; 1425 } 1426 1427 if (!(ifr.ifr_flags & IFF_UP)) { 1428 ifr.ifr_flags |= IFF_UP; 1429 if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { 1430 debug_f("activate interface %s: %s", ifr.ifr_name, 1431 strerror(errno)); 1432 goto failed; 1433 } 1434 } 1435 1436 if (ifname != NULL) 1437 *ifname = xstrdup(ifr.ifr_name); 1438 1439 close(sock); 1440 return fd; 1441 1442 failed: 1443 if (fd >= 0) 1444 close(fd); 1445 if (sock >= 0) 1446 close(sock); 1447 return -1; 1448 } 1449 1450 void 1451 sanitise_stdfd(void) 1452 { 1453 int nullfd, dupfd; 1454 1455 if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1456 fprintf(stderr, "Couldn't open /dev/null: %s\n", 1457 strerror(errno)); 1458 exit(1); 1459 } 1460 while (++dupfd <= STDERR_FILENO) { 1461 /* Only populate closed fds. */ 1462 if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { 1463 if (dup2(nullfd, dupfd) == -1) { 1464 fprintf(stderr, "dup2: %s\n", strerror(errno)); 1465 exit(1); 1466 } 1467 } 1468 } 1469 if (nullfd > STDERR_FILENO) 1470 close(nullfd); 1471 } 1472 1473 char * 1474 tohex(const void *vp, size_t l) 1475 { 1476 const u_char *p = (const u_char *)vp; 1477 char b[3], *r; 1478 size_t i, hl; 1479 1480 if (l > 65536) 1481 return xstrdup("tohex: length > 65536"); 1482 1483 hl = l * 2 + 1; 1484 r = xcalloc(1, hl); 1485 for (i = 0; i < l; i++) { 1486 snprintf(b, sizeof(b), "%02x", p[i]); 1487 strlcat(r, b, hl); 1488 } 1489 return (r); 1490 } 1491 1492 /* 1493 * Extend string *sp by the specified format. If *sp is not NULL (or empty), 1494 * then the separator 'sep' will be prepended before the formatted arguments. 1495 * Extended strings are heap allocated. 1496 */ 1497 void 1498 xextendf(char **sp, const char *sep, const char *fmt, ...) 1499 { 1500 va_list ap; 1501 char *tmp1, *tmp2; 1502 1503 va_start(ap, fmt); 1504 xvasprintf(&tmp1, fmt, ap); 1505 va_end(ap); 1506 1507 if (*sp == NULL || **sp == '\0') { 1508 free(*sp); 1509 *sp = tmp1; 1510 return; 1511 } 1512 xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); 1513 free(tmp1); 1514 free(*sp); 1515 *sp = tmp2; 1516 } 1517 1518 1519 u_int64_t 1520 get_u64(const void *vp) 1521 { 1522 const u_char *p = (const u_char *)vp; 1523 u_int64_t v; 1524 1525 v = (u_int64_t)p[0] << 56; 1526 v |= (u_int64_t)p[1] << 48; 1527 v |= (u_int64_t)p[2] << 40; 1528 v |= (u_int64_t)p[3] << 32; 1529 v |= (u_int64_t)p[4] << 24; 1530 v |= (u_int64_t)p[5] << 16; 1531 v |= (u_int64_t)p[6] << 8; 1532 v |= (u_int64_t)p[7]; 1533 1534 return (v); 1535 } 1536 1537 u_int32_t 1538 get_u32(const void *vp) 1539 { 1540 const u_char *p = (const u_char *)vp; 1541 u_int32_t v; 1542 1543 v = (u_int32_t)p[0] << 24; 1544 v |= (u_int32_t)p[1] << 16; 1545 v |= (u_int32_t)p[2] << 8; 1546 v |= (u_int32_t)p[3]; 1547 1548 return (v); 1549 } 1550 1551 u_int32_t 1552 get_u32_le(const void *vp) 1553 { 1554 const u_char *p = (const u_char *)vp; 1555 u_int32_t v; 1556 1557 v = (u_int32_t)p[0]; 1558 v |= (u_int32_t)p[1] << 8; 1559 v |= (u_int32_t)p[2] << 16; 1560 v |= (u_int32_t)p[3] << 24; 1561 1562 return (v); 1563 } 1564 1565 u_int16_t 1566 get_u16(const void *vp) 1567 { 1568 const u_char *p = (const u_char *)vp; 1569 u_int16_t v; 1570 1571 v = (u_int16_t)p[0] << 8; 1572 v |= (u_int16_t)p[1]; 1573 1574 return (v); 1575 } 1576 1577 void 1578 put_u64(void *vp, u_int64_t v) 1579 { 1580 u_char *p = (u_char *)vp; 1581 1582 p[0] = (u_char)(v >> 56) & 0xff; 1583 p[1] = (u_char)(v >> 48) & 0xff; 1584 p[2] = (u_char)(v >> 40) & 0xff; 1585 p[3] = (u_char)(v >> 32) & 0xff; 1586 p[4] = (u_char)(v >> 24) & 0xff; 1587 p[5] = (u_char)(v >> 16) & 0xff; 1588 p[6] = (u_char)(v >> 8) & 0xff; 1589 p[7] = (u_char)v & 0xff; 1590 } 1591 1592 void 1593 put_u32(void *vp, u_int32_t v) 1594 { 1595 u_char *p = (u_char *)vp; 1596 1597 p[0] = (u_char)(v >> 24) & 0xff; 1598 p[1] = (u_char)(v >> 16) & 0xff; 1599 p[2] = (u_char)(v >> 8) & 0xff; 1600 p[3] = (u_char)v & 0xff; 1601 } 1602 1603 void 1604 put_u32_le(void *vp, u_int32_t v) 1605 { 1606 u_char *p = (u_char *)vp; 1607 1608 p[0] = (u_char)v & 0xff; 1609 p[1] = (u_char)(v >> 8) & 0xff; 1610 p[2] = (u_char)(v >> 16) & 0xff; 1611 p[3] = (u_char)(v >> 24) & 0xff; 1612 } 1613 1614 void 1615 put_u16(void *vp, u_int16_t v) 1616 { 1617 u_char *p = (u_char *)vp; 1618 1619 p[0] = (u_char)(v >> 8) & 0xff; 1620 p[1] = (u_char)v & 0xff; 1621 } 1622 1623 void 1624 ms_subtract_diff(struct timeval *start, int *ms) 1625 { 1626 struct timeval diff, finish; 1627 1628 monotime_tv(&finish); 1629 timersub(&finish, start, &diff); 1630 *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); 1631 } 1632 1633 void 1634 ms_to_timespec(struct timespec *ts, int ms) 1635 { 1636 if (ms < 0) 1637 ms = 0; 1638 ts->tv_sec = ms / 1000; 1639 ts->tv_nsec = (ms % 1000) * 1000 * 1000; 1640 } 1641 1642 void 1643 monotime_ts(struct timespec *ts) 1644 { 1645 if (clock_gettime(CLOCK_MONOTONIC, ts) != 0) 1646 fatal("clock_gettime: %s", strerror(errno)); 1647 } 1648 1649 void 1650 monotime_tv(struct timeval *tv) 1651 { 1652 struct timespec ts; 1653 1654 monotime_ts(&ts); 1655 tv->tv_sec = ts.tv_sec; 1656 tv->tv_usec = ts.tv_nsec / 1000; 1657 } 1658 1659 time_t 1660 monotime(void) 1661 { 1662 struct timespec ts; 1663 1664 monotime_ts(&ts); 1665 return (ts.tv_sec); 1666 } 1667 1668 double 1669 monotime_double(void) 1670 { 1671 struct timespec ts; 1672 1673 monotime_ts(&ts); 1674 return (double)ts.tv_sec + (double)ts.tv_nsec / 1000000000.0; 1675 } 1676 1677 void 1678 bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) 1679 { 1680 bw->buflen = buflen; 1681 bw->rate = kbps; 1682 bw->thresh = buflen; 1683 bw->lamt = 0; 1684 timerclear(&bw->bwstart); 1685 timerclear(&bw->bwend); 1686 } 1687 1688 /* Callback from read/write loop to insert bandwidth-limiting delays */ 1689 void 1690 bandwidth_limit(struct bwlimit *bw, size_t read_len) 1691 { 1692 u_int64_t waitlen; 1693 struct timespec ts, rm; 1694 1695 bw->lamt += read_len; 1696 if (!timerisset(&bw->bwstart)) { 1697 monotime_tv(&bw->bwstart); 1698 return; 1699 } 1700 if (bw->lamt < bw->thresh) 1701 return; 1702 1703 monotime_tv(&bw->bwend); 1704 timersub(&bw->bwend, &bw->bwstart, &bw->bwend); 1705 if (!timerisset(&bw->bwend)) 1706 return; 1707 1708 bw->lamt *= 8; 1709 waitlen = (double)1000000L * bw->lamt / bw->rate; 1710 1711 bw->bwstart.tv_sec = waitlen / 1000000L; 1712 bw->bwstart.tv_usec = waitlen % 1000000L; 1713 1714 if (timercmp(&bw->bwstart, &bw->bwend, >)) { 1715 timersub(&bw->bwstart, &bw->bwend, &bw->bwend); 1716 1717 /* Adjust the wait time */ 1718 if (bw->bwend.tv_sec) { 1719 bw->thresh /= 2; 1720 if (bw->thresh < bw->buflen / 4) 1721 bw->thresh = bw->buflen / 4; 1722 } else if (bw->bwend.tv_usec < 10000) { 1723 bw->thresh *= 2; 1724 if (bw->thresh > bw->buflen * 8) 1725 bw->thresh = bw->buflen * 8; 1726 } 1727 1728 TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); 1729 while (nanosleep(&ts, &rm) == -1) { 1730 if (errno != EINTR) 1731 break; 1732 ts = rm; 1733 } 1734 } 1735 1736 bw->lamt = 0; 1737 monotime_tv(&bw->bwstart); 1738 } 1739 1740 /* Make a template filename for mk[sd]temp() */ 1741 void 1742 mktemp_proto(char *s, size_t len) 1743 { 1744 const char *tmpdir; 1745 int r; 1746 1747 if ((tmpdir = getenv("TMPDIR")) != NULL) { 1748 r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); 1749 if (r > 0 && (size_t)r < len) 1750 return; 1751 } 1752 r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); 1753 if (r < 0 || (size_t)r >= len) 1754 fatal_f("template string too short"); 1755 } 1756 1757 static const struct { 1758 const char *name; 1759 int value; 1760 } ipqos[] = { 1761 { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ 1762 { "af11", IPTOS_DSCP_AF11 }, 1763 { "af12", IPTOS_DSCP_AF12 }, 1764 { "af13", IPTOS_DSCP_AF13 }, 1765 { "af21", IPTOS_DSCP_AF21 }, 1766 { "af22", IPTOS_DSCP_AF22 }, 1767 { "af23", IPTOS_DSCP_AF23 }, 1768 { "af31", IPTOS_DSCP_AF31 }, 1769 { "af32", IPTOS_DSCP_AF32 }, 1770 { "af33", IPTOS_DSCP_AF33 }, 1771 { "af41", IPTOS_DSCP_AF41 }, 1772 { "af42", IPTOS_DSCP_AF42 }, 1773 { "af43", IPTOS_DSCP_AF43 }, 1774 { "cs0", IPTOS_DSCP_CS0 }, 1775 { "cs1", IPTOS_DSCP_CS1 }, 1776 { "cs2", IPTOS_DSCP_CS2 }, 1777 { "cs3", IPTOS_DSCP_CS3 }, 1778 { "cs4", IPTOS_DSCP_CS4 }, 1779 { "cs5", IPTOS_DSCP_CS5 }, 1780 { "cs6", IPTOS_DSCP_CS6 }, 1781 { "cs7", IPTOS_DSCP_CS7 }, 1782 { "ef", IPTOS_DSCP_EF }, 1783 { "le", IPTOS_DSCP_LE }, 1784 { "lowdelay", IPTOS_LOWDELAY }, 1785 { "throughput", IPTOS_THROUGHPUT }, 1786 { "reliability", IPTOS_RELIABILITY }, 1787 { NULL, -1 } 1788 }; 1789 1790 int 1791 parse_ipqos(const char *cp) 1792 { 1793 const char *errstr; 1794 u_int i; 1795 int val; 1796 1797 if (cp == NULL) 1798 return -1; 1799 for (i = 0; ipqos[i].name != NULL; i++) { 1800 if (strcasecmp(cp, ipqos[i].name) == 0) 1801 return ipqos[i].value; 1802 } 1803 /* Try parsing as an integer */ 1804 val = (int)strtonum(cp, 0, 255, &errstr); 1805 if (errstr) 1806 return -1; 1807 return val; 1808 } 1809 1810 const char * 1811 iptos2str(int iptos) 1812 { 1813 int i; 1814 static char iptos_str[sizeof "0xff"]; 1815 1816 for (i = 0; ipqos[i].name != NULL; i++) { 1817 if (ipqos[i].value == iptos) 1818 return ipqos[i].name; 1819 } 1820 snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); 1821 return iptos_str; 1822 } 1823 1824 void 1825 lowercase(char *s) 1826 { 1827 for (; *s; s++) 1828 *s = tolower((u_char)*s); 1829 } 1830 1831 int 1832 unix_listener(const char *path, int backlog, int unlink_first) 1833 { 1834 struct sockaddr_un sunaddr; 1835 int saved_errno, sock; 1836 1837 memset(&sunaddr, 0, sizeof(sunaddr)); 1838 sunaddr.sun_family = AF_UNIX; 1839 if (strlcpy(sunaddr.sun_path, path, 1840 sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { 1841 error_f("path \"%s\" too long for Unix domain socket", path); 1842 errno = ENAMETOOLONG; 1843 return -1; 1844 } 1845 1846 sock = socket(PF_UNIX, SOCK_STREAM, 0); 1847 if (sock == -1) { 1848 saved_errno = errno; 1849 error_f("socket: %.100s", strerror(errno)); 1850 errno = saved_errno; 1851 return -1; 1852 } 1853 if (unlink_first == 1) { 1854 if (unlink(path) != 0 && errno != ENOENT) 1855 error("unlink(%s): %.100s", path, strerror(errno)); 1856 } 1857 if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { 1858 saved_errno = errno; 1859 error_f("cannot bind to path %s: %s", path, strerror(errno)); 1860 close(sock); 1861 errno = saved_errno; 1862 return -1; 1863 } 1864 if (listen(sock, backlog) == -1) { 1865 saved_errno = errno; 1866 error_f("cannot listen on path %s: %s", path, strerror(errno)); 1867 close(sock); 1868 unlink(path); 1869 errno = saved_errno; 1870 return -1; 1871 } 1872 return sock; 1873 } 1874 1875 /* 1876 * Compares two strings that maybe be NULL. Returns non-zero if strings 1877 * are both NULL or are identical, returns zero otherwise. 1878 */ 1879 static int 1880 strcmp_maybe_null(const char *a, const char *b) 1881 { 1882 if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) 1883 return 0; 1884 if (a != NULL && strcmp(a, b) != 0) 1885 return 0; 1886 return 1; 1887 } 1888 1889 /* 1890 * Compare two forwards, returning non-zero if they are identical or 1891 * zero otherwise. 1892 */ 1893 int 1894 forward_equals(const struct Forward *a, const struct Forward *b) 1895 { 1896 if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) 1897 return 0; 1898 if (a->listen_port != b->listen_port) 1899 return 0; 1900 if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) 1901 return 0; 1902 if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) 1903 return 0; 1904 if (a->connect_port != b->connect_port) 1905 return 0; 1906 if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) 1907 return 0; 1908 /* allocated_port and handle are not checked */ 1909 return 1; 1910 } 1911 1912 /* returns 1 if process is already daemonized, 0 otherwise */ 1913 int 1914 daemonized(void) 1915 { 1916 int fd; 1917 1918 if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { 1919 close(fd); 1920 return 0; /* have controlling terminal */ 1921 } 1922 if (getppid() != 1) 1923 return 0; /* parent is not init */ 1924 if (getsid(0) != getpid()) 1925 return 0; /* not session leader */ 1926 debug3("already daemonized"); 1927 return 1; 1928 } 1929 1930 /* 1931 * Splits 's' into an argument vector. Handles quoted string and basic 1932 * escape characters (\\, \", \'). Caller must free the argument vector 1933 * and its members. 1934 */ 1935 int 1936 argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) 1937 { 1938 int r = SSH_ERR_INTERNAL_ERROR; 1939 int argc = 0, quote, i, j; 1940 char *arg, **argv = xcalloc(1, sizeof(*argv)); 1941 1942 *argvp = NULL; 1943 *argcp = 0; 1944 1945 for (i = 0; s[i] != '\0'; i++) { 1946 /* Skip leading whitespace */ 1947 if (s[i] == ' ' || s[i] == '\t') 1948 continue; 1949 if (terminate_on_comment && s[i] == '#') 1950 break; 1951 /* Start of a token */ 1952 quote = 0; 1953 1954 argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); 1955 arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); 1956 argv[argc] = NULL; 1957 1958 /* Copy the token in, removing escapes */ 1959 for (j = 0; s[i] != '\0'; i++) { 1960 if (s[i] == '\\') { 1961 if (s[i + 1] == '\'' || 1962 s[i + 1] == '\"' || 1963 s[i + 1] == '\\' || 1964 (quote == 0 && s[i + 1] == ' ')) { 1965 i++; /* Skip '\' */ 1966 arg[j++] = s[i]; 1967 } else { 1968 /* Unrecognised escape */ 1969 arg[j++] = s[i]; 1970 } 1971 } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) 1972 break; /* done */ 1973 else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) 1974 quote = s[i]; /* quote start */ 1975 else if (quote != 0 && s[i] == quote) 1976 quote = 0; /* quote end */ 1977 else 1978 arg[j++] = s[i]; 1979 } 1980 if (s[i] == '\0') { 1981 if (quote != 0) { 1982 /* Ran out of string looking for close quote */ 1983 r = SSH_ERR_INVALID_FORMAT; 1984 goto out; 1985 } 1986 break; 1987 } 1988 } 1989 /* Success */ 1990 *argcp = argc; 1991 *argvp = argv; 1992 argc = 0; 1993 argv = NULL; 1994 r = 0; 1995 out: 1996 if (argc != 0 && argv != NULL) { 1997 for (i = 0; i < argc; i++) 1998 free(argv[i]); 1999 free(argv); 2000 } 2001 return r; 2002 } 2003 2004 /* 2005 * Reassemble an argument vector into a string, quoting and escaping as 2006 * necessary. Caller must free returned string. 2007 */ 2008 char * 2009 argv_assemble(int argc, char **argv) 2010 { 2011 int i, j, ws, r; 2012 char c, *ret; 2013 struct sshbuf *buf, *arg; 2014 2015 if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) 2016 fatal_f("sshbuf_new failed"); 2017 2018 for (i = 0; i < argc; i++) { 2019 ws = 0; 2020 sshbuf_reset(arg); 2021 for (j = 0; argv[i][j] != '\0'; j++) { 2022 r = 0; 2023 c = argv[i][j]; 2024 switch (c) { 2025 case ' ': 2026 case '\t': 2027 ws = 1; 2028 r = sshbuf_put_u8(arg, c); 2029 break; 2030 case '\\': 2031 case '\'': 2032 case '"': 2033 if ((r = sshbuf_put_u8(arg, '\\')) != 0) 2034 break; 2035 /* FALLTHROUGH */ 2036 default: 2037 r = sshbuf_put_u8(arg, c); 2038 break; 2039 } 2040 if (r != 0) 2041 fatal_fr(r, "sshbuf_put_u8"); 2042 } 2043 if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || 2044 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || 2045 (r = sshbuf_putb(buf, arg)) != 0 || 2046 (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) 2047 fatal_fr(r, "assemble"); 2048 } 2049 if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) 2050 fatal_f("malloc failed"); 2051 memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); 2052 ret[sshbuf_len(buf)] = '\0'; 2053 sshbuf_free(buf); 2054 sshbuf_free(arg); 2055 return ret; 2056 } 2057 2058 char * 2059 argv_next(int *argcp, char ***argvp) 2060 { 2061 char *ret = (*argvp)[0]; 2062 2063 if (*argcp > 0 && ret != NULL) { 2064 (*argcp)--; 2065 (*argvp)++; 2066 } 2067 return ret; 2068 } 2069 2070 void 2071 argv_consume(int *argcp) 2072 { 2073 *argcp = 0; 2074 } 2075 2076 void 2077 argv_free(char **av, int ac) 2078 { 2079 int i; 2080 2081 if (av == NULL) 2082 return; 2083 for (i = 0; i < ac; i++) 2084 free(av[i]); 2085 free(av); 2086 } 2087 2088 /* Returns 0 if pid exited cleanly, non-zero otherwise */ 2089 int 2090 exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) 2091 { 2092 int status; 2093 2094 while (waitpid(pid, &status, 0) == -1) { 2095 if (errno != EINTR) { 2096 error("%s waitpid: %s", tag, strerror(errno)); 2097 return -1; 2098 } 2099 } 2100 if (WIFSIGNALED(status)) { 2101 error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); 2102 return -1; 2103 } else if (WEXITSTATUS(status) != 0) { 2104 do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, 2105 "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); 2106 return -1; 2107 } 2108 return 0; 2109 } 2110 2111 /* 2112 * Check a given path for security. This is defined as all components 2113 * of the path to the file must be owned by either the owner of 2114 * of the file or root and no directories must be group or world writable. 2115 * 2116 * XXX Should any specific check be done for sym links ? 2117 * 2118 * Takes a file name, its stat information (preferably from fstat() to 2119 * avoid races), the uid of the expected owner, their home directory and an 2120 * error buffer plus max size as arguments. 2121 * 2122 * Returns 0 on success and -1 on failure 2123 */ 2124 int 2125 safe_path(const char *name, struct stat *stp, const char *pw_dir, 2126 uid_t uid, char *err, size_t errlen) 2127 { 2128 char buf[PATH_MAX], homedir[PATH_MAX]; 2129 char *cp; 2130 int comparehome = 0; 2131 struct stat st; 2132 2133 if (realpath(name, buf) == NULL) { 2134 snprintf(err, errlen, "realpath %s failed: %s", name, 2135 strerror(errno)); 2136 return -1; 2137 } 2138 if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) 2139 comparehome = 1; 2140 2141 if (!S_ISREG(stp->st_mode)) { 2142 snprintf(err, errlen, "%s is not a regular file", buf); 2143 return -1; 2144 } 2145 if ((stp->st_uid != 0 && stp->st_uid != uid) || 2146 (stp->st_mode & 022) != 0) { 2147 snprintf(err, errlen, "bad ownership or modes for file %s", 2148 buf); 2149 return -1; 2150 } 2151 2152 /* for each component of the canonical path, walking upwards */ 2153 for (;;) { 2154 if ((cp = dirname(buf)) == NULL) { 2155 snprintf(err, errlen, "dirname() failed"); 2156 return -1; 2157 } 2158 strlcpy(buf, cp, sizeof(buf)); 2159 2160 if (stat(buf, &st) == -1 || 2161 (st.st_uid != 0 && st.st_uid != uid) || 2162 (st.st_mode & 022) != 0) { 2163 snprintf(err, errlen, 2164 "bad ownership or modes for directory %s", buf); 2165 return -1; 2166 } 2167 2168 /* If are past the homedir then we can stop */ 2169 if (comparehome && strcmp(homedir, buf) == 0) 2170 break; 2171 2172 /* 2173 * dirname should always complete with a "/" path, 2174 * but we can be paranoid and check for "." too 2175 */ 2176 if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) 2177 break; 2178 } 2179 return 0; 2180 } 2181 2182 /* 2183 * Version of safe_path() that accepts an open file descriptor to 2184 * avoid races. 2185 * 2186 * Returns 0 on success and -1 on failure 2187 */ 2188 int 2189 safe_path_fd(int fd, const char *file, struct passwd *pw, 2190 char *err, size_t errlen) 2191 { 2192 struct stat st; 2193 2194 /* check the open file to avoid races */ 2195 if (fstat(fd, &st) == -1) { 2196 snprintf(err, errlen, "cannot stat file %s: %s", 2197 file, strerror(errno)); 2198 return -1; 2199 } 2200 return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); 2201 } 2202 2203 /* 2204 * Sets the value of the given variable in the environment. If the variable 2205 * already exists, its value is overridden. 2206 */ 2207 void 2208 child_set_env(char ***envp, u_int *envsizep, const char *name, 2209 const char *value) 2210 { 2211 char **env; 2212 u_int envsize; 2213 u_int i, namelen; 2214 2215 if (strchr(name, '=') != NULL) { 2216 error("Invalid environment variable \"%.100s\"", name); 2217 return; 2218 } 2219 2220 /* 2221 * Find the slot where the value should be stored. If the variable 2222 * already exists, we reuse the slot; otherwise we append a new slot 2223 * at the end of the array, expanding if necessary. 2224 */ 2225 env = *envp; 2226 namelen = strlen(name); 2227 for (i = 0; env[i]; i++) 2228 if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') 2229 break; 2230 if (env[i]) { 2231 /* Reuse the slot. */ 2232 free(env[i]); 2233 } else { 2234 /* New variable. Expand if necessary. */ 2235 envsize = *envsizep; 2236 if (i >= envsize - 1) { 2237 if (envsize >= 1000) 2238 fatal("child_set_env: too many env vars"); 2239 envsize += 50; 2240 env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); 2241 *envsizep = envsize; 2242 } 2243 /* Need to set the NULL pointer at end of array beyond the new slot. */ 2244 env[i + 1] = NULL; 2245 } 2246 2247 /* Allocate space and format the variable in the appropriate slot. */ 2248 /* XXX xasprintf */ 2249 env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); 2250 snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); 2251 } 2252 2253 /* 2254 * Check and optionally lowercase a domain name, also removes trailing '.' 2255 * Returns 1 on success and 0 on failure, storing an error message in errstr. 2256 */ 2257 int 2258 valid_domain(char *name, int makelower, const char **errstr) 2259 { 2260 size_t i, l = strlen(name); 2261 u_char c, last = '\0'; 2262 static char errbuf[256]; 2263 2264 if (l == 0) { 2265 strlcpy(errbuf, "empty domain name", sizeof(errbuf)); 2266 goto bad; 2267 } 2268 if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { 2269 snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " 2270 "starts with invalid character", name); 2271 goto bad; 2272 } 2273 for (i = 0; i < l; i++) { 2274 c = tolower((u_char)name[i]); 2275 if (makelower) 2276 name[i] = (char)c; 2277 if (last == '.' && c == '.') { 2278 snprintf(errbuf, sizeof(errbuf), "domain name " 2279 "\"%.100s\" contains consecutive separators", name); 2280 goto bad; 2281 } 2282 if (c != '.' && c != '-' && !isalnum(c) && 2283 c != '_') /* technically invalid, but common */ { 2284 snprintf(errbuf, sizeof(errbuf), "domain name " 2285 "\"%.100s\" contains invalid characters", name); 2286 goto bad; 2287 } 2288 last = c; 2289 } 2290 if (name[l - 1] == '.') 2291 name[l - 1] = '\0'; 2292 if (errstr != NULL) 2293 *errstr = NULL; 2294 return 1; 2295 bad: 2296 if (errstr != NULL) 2297 *errstr = errbuf; 2298 return 0; 2299 } 2300 2301 /* 2302 * Verify that a environment variable name (not including initial '$') is 2303 * valid; consisting of one or more alphanumeric or underscore characters only. 2304 * Returns 1 on valid, 0 otherwise. 2305 */ 2306 int 2307 valid_env_name(const char *name) 2308 { 2309 const char *cp; 2310 2311 if (name[0] == '\0') 2312 return 0; 2313 for (cp = name; *cp != '\0'; cp++) { 2314 if (!isalnum((u_char)*cp) && *cp != '_') 2315 return 0; 2316 } 2317 return 1; 2318 } 2319 2320 const char * 2321 atoi_err(const char *nptr, int *val) 2322 { 2323 const char *errstr = NULL; 2324 2325 if (nptr == NULL || *nptr == '\0') 2326 return "missing"; 2327 *val = strtonum(nptr, 0, INT_MAX, &errstr); 2328 return errstr; 2329 } 2330 2331 int 2332 parse_absolute_time(const char *s, uint64_t *tp) 2333 { 2334 struct tm tm; 2335 time_t tt; 2336 char buf[32], *fmt; 2337 const char *cp; 2338 size_t l; 2339 int is_utc = 0; 2340 2341 *tp = 0; 2342 2343 l = strlen(s); 2344 if (l > 1 && strcasecmp(s + l - 1, "Z") == 0) { 2345 is_utc = 1; 2346 l--; 2347 } else if (l > 3 && strcasecmp(s + l - 3, "UTC") == 0) { 2348 is_utc = 1; 2349 l -= 3; 2350 } 2351 /* 2352 * POSIX strptime says "The application shall ensure that there 2353 * is white-space or other non-alphanumeric characters between 2354 * any two conversion specifications" so arrange things this way. 2355 */ 2356 switch (l) { 2357 case 8: /* YYYYMMDD */ 2358 fmt = "%Y-%m-%d"; 2359 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); 2360 break; 2361 case 12: /* YYYYMMDDHHMM */ 2362 fmt = "%Y-%m-%dT%H:%M"; 2363 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", 2364 s, s + 4, s + 6, s + 8, s + 10); 2365 break; 2366 case 14: /* YYYYMMDDHHMMSS */ 2367 fmt = "%Y-%m-%dT%H:%M:%S"; 2368 snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", 2369 s, s + 4, s + 6, s + 8, s + 10, s + 12); 2370 break; 2371 default: 2372 return SSH_ERR_INVALID_FORMAT; 2373 } 2374 2375 memset(&tm, 0, sizeof(tm)); 2376 if ((cp = strptime(buf, fmt, &tm)) == NULL || *cp != '\0') 2377 return SSH_ERR_INVALID_FORMAT; 2378 if (is_utc) { 2379 if ((tt = timegm(&tm)) < 0) 2380 return SSH_ERR_INVALID_FORMAT; 2381 } else { 2382 if ((tt = mktime(&tm)) < 0) 2383 return SSH_ERR_INVALID_FORMAT; 2384 } 2385 /* success */ 2386 *tp = (uint64_t)tt; 2387 return 0; 2388 } 2389 2390 void 2391 format_absolute_time(uint64_t t, char *buf, size_t len) 2392 { 2393 time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; 2394 struct tm tm; 2395 2396 localtime_r(&tt, &tm); 2397 strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); 2398 } 2399 2400 /* 2401 * Parse a "pattern=interval" clause (e.g. a ChannelTimeout). 2402 * Returns 0 on success or non-zero on failure. 2403 * Caller must free *typep. 2404 */ 2405 int 2406 parse_pattern_interval(const char *s, char **typep, int *secsp) 2407 { 2408 char *cp, *sdup; 2409 int secs; 2410 2411 if (typep != NULL) 2412 *typep = NULL; 2413 if (secsp != NULL) 2414 *secsp = 0; 2415 if (s == NULL) 2416 return -1; 2417 sdup = xstrdup(s); 2418 2419 if ((cp = strchr(sdup, '=')) == NULL || cp == sdup) { 2420 free(sdup); 2421 return -1; 2422 } 2423 *cp++ = '\0'; 2424 if ((secs = convtime(cp)) < 0) { 2425 free(sdup); 2426 return -1; 2427 } 2428 /* success */ 2429 if (typep != NULL) 2430 *typep = xstrdup(sdup); 2431 if (secsp != NULL) 2432 *secsp = secs; 2433 free(sdup); 2434 return 0; 2435 } 2436 2437 /* check if path is absolute */ 2438 int 2439 path_absolute(const char *path) 2440 { 2441 return (*path == '/') ? 1 : 0; 2442 } 2443 2444 void 2445 skip_space(char **cpp) 2446 { 2447 char *cp; 2448 2449 for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) 2450 ; 2451 *cpp = cp; 2452 } 2453 2454 /* authorized_key-style options parsing helpers */ 2455 2456 /* 2457 * Match flag 'opt' in *optsp, and if allow_negate is set then also match 2458 * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 2459 * if negated option matches. 2460 * If the option or negated option matches, then *optsp is updated to 2461 * point to the first character after the option. 2462 */ 2463 int 2464 opt_flag(const char *opt, int allow_negate, const char **optsp) 2465 { 2466 size_t opt_len = strlen(opt); 2467 const char *opts = *optsp; 2468 int negate = 0; 2469 2470 if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { 2471 opts += 3; 2472 negate = 1; 2473 } 2474 if (strncasecmp(opts, opt, opt_len) == 0) { 2475 *optsp = opts + opt_len; 2476 return negate ? 0 : 1; 2477 } 2478 return -1; 2479 } 2480 2481 char * 2482 opt_dequote(const char **sp, const char **errstrp) 2483 { 2484 const char *s = *sp; 2485 char *ret; 2486 size_t i; 2487 2488 *errstrp = NULL; 2489 if (*s != '"') { 2490 *errstrp = "missing start quote"; 2491 return NULL; 2492 } 2493 s++; 2494 if ((ret = malloc(strlen((s)) + 1)) == NULL) { 2495 *errstrp = "memory allocation failed"; 2496 return NULL; 2497 } 2498 for (i = 0; *s != '\0' && *s != '"';) { 2499 if (s[0] == '\\' && s[1] == '"') 2500 s++; 2501 ret[i++] = *s++; 2502 } 2503 if (*s == '\0') { 2504 *errstrp = "missing end quote"; 2505 free(ret); 2506 return NULL; 2507 } 2508 ret[i] = '\0'; 2509 s++; 2510 *sp = s; 2511 return ret; 2512 } 2513 2514 int 2515 opt_match(const char **opts, const char *term) 2516 { 2517 if (strncasecmp((*opts), term, strlen(term)) == 0 && 2518 (*opts)[strlen(term)] == '=') { 2519 *opts += strlen(term) + 1; 2520 return 1; 2521 } 2522 return 0; 2523 } 2524 2525 void 2526 opt_array_append2(const char *file, const int line, const char *directive, 2527 char ***array, int **iarray, u_int *lp, const char *s, int i) 2528 { 2529 2530 if (*lp >= INT_MAX) 2531 fatal("%s line %d: Too many %s entries", file, line, directive); 2532 2533 if (iarray != NULL) { 2534 *iarray = xrecallocarray(*iarray, *lp, *lp + 1, 2535 sizeof(**iarray)); 2536 (*iarray)[*lp] = i; 2537 } 2538 2539 *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); 2540 (*array)[*lp] = xstrdup(s); 2541 (*lp)++; 2542 } 2543 2544 void 2545 opt_array_append(const char *file, const int line, const char *directive, 2546 char ***array, u_int *lp, const char *s) 2547 { 2548 opt_array_append2(file, line, directive, array, NULL, lp, s, 0); 2549 } 2550 2551 void 2552 opt_array_free2(char **array, int **iarray, u_int l) 2553 { 2554 u_int i; 2555 2556 if (array == NULL || l == 0) 2557 return; 2558 for (i = 0; i < l; i++) 2559 free(array[i]); 2560 free(array); 2561 free(iarray); 2562 } 2563 2564 sshsig_t 2565 ssh_signal(int signum, sshsig_t handler) 2566 { 2567 struct sigaction sa, osa; 2568 2569 /* mask all other signals while in handler */ 2570 memset(&sa, 0, sizeof(sa)); 2571 sa.sa_handler = handler; 2572 sigfillset(&sa.sa_mask); 2573 if (signum != SIGALRM) 2574 sa.sa_flags = SA_RESTART; 2575 if (sigaction(signum, &sa, &osa) == -1) { 2576 debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); 2577 return SIG_ERR; 2578 } 2579 return osa.sa_handler; 2580 } 2581 2582 int 2583 stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) 2584 { 2585 int devnull, ret = 0; 2586 2587 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2588 error_f("open %s: %s", _PATH_DEVNULL, 2589 strerror(errno)); 2590 return -1; 2591 } 2592 if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || 2593 (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || 2594 (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { 2595 error_f("dup2: %s", strerror(errno)); 2596 ret = -1; 2597 } 2598 if (devnull > STDERR_FILENO) 2599 close(devnull); 2600 return ret; 2601 } 2602 2603 /* 2604 * Runs command in a subprocess with a minimal environment. 2605 * Returns pid on success, 0 on failure. 2606 * The child stdout and stderr maybe captured, left attached or sent to 2607 * /dev/null depending on the contents of flags. 2608 * "tag" is prepended to log messages. 2609 * NB. "command" is only used for logging; the actual command executed is 2610 * av[0]. 2611 */ 2612 pid_t 2613 subprocess(const char *tag, const char *command, 2614 int ac, char **av, FILE **child, u_int flags, 2615 struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) 2616 { 2617 FILE *f = NULL; 2618 struct stat st; 2619 int fd, devnull, p[2], i; 2620 pid_t pid; 2621 char *cp, errmsg[512]; 2622 u_int nenv = 0; 2623 char **env = NULL; 2624 2625 /* If dropping privs, then must specify user and restore function */ 2626 if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { 2627 error("%s: inconsistent arguments", tag); /* XXX fatal? */ 2628 return 0; 2629 } 2630 if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { 2631 error("%s: no user for current uid", tag); 2632 return 0; 2633 } 2634 if (child != NULL) 2635 *child = NULL; 2636 2637 debug3_f("%s command \"%s\" running as %s (flags 0x%x)", 2638 tag, command, pw->pw_name, flags); 2639 2640 /* Check consistency */ 2641 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2642 (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { 2643 error_f("inconsistent flags"); 2644 return 0; 2645 } 2646 if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { 2647 error_f("inconsistent flags/output"); 2648 return 0; 2649 } 2650 2651 /* 2652 * If executing an explicit binary, then verify the it exists 2653 * and appears safe-ish to execute 2654 */ 2655 if (!path_absolute(av[0])) { 2656 error("%s path is not absolute", tag); 2657 return 0; 2658 } 2659 if (drop_privs != NULL) 2660 drop_privs(pw); 2661 if (stat(av[0], &st) == -1) { 2662 error("Could not stat %s \"%s\": %s", tag, 2663 av[0], strerror(errno)); 2664 goto restore_return; 2665 } 2666 if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && 2667 safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { 2668 error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); 2669 goto restore_return; 2670 } 2671 /* Prepare to keep the child's stdout if requested */ 2672 if (pipe(p) == -1) { 2673 error("%s: pipe: %s", tag, strerror(errno)); 2674 restore_return: 2675 if (restore_privs != NULL) 2676 restore_privs(); 2677 return 0; 2678 } 2679 if (restore_privs != NULL) 2680 restore_privs(); 2681 2682 switch ((pid = fork())) { 2683 case -1: /* error */ 2684 error("%s: fork: %s", tag, strerror(errno)); 2685 close(p[0]); 2686 close(p[1]); 2687 return 0; 2688 case 0: /* child */ 2689 /* Prepare a minimal environment for the child. */ 2690 if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { 2691 nenv = 5; 2692 env = xcalloc(sizeof(*env), nenv); 2693 child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); 2694 child_set_env(&env, &nenv, "USER", pw->pw_name); 2695 child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); 2696 child_set_env(&env, &nenv, "HOME", pw->pw_dir); 2697 if ((cp = getenv("LANG")) != NULL) 2698 child_set_env(&env, &nenv, "LANG", cp); 2699 } 2700 2701 for (i = 1; i < NSIG; i++) 2702 ssh_signal(i, SIG_DFL); 2703 2704 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 2705 error("%s: open %s: %s", tag, _PATH_DEVNULL, 2706 strerror(errno)); 2707 _exit(1); 2708 } 2709 if (dup2(devnull, STDIN_FILENO) == -1) { 2710 error("%s: dup2: %s", tag, strerror(errno)); 2711 _exit(1); 2712 } 2713 2714 /* Set up stdout as requested; leave stderr in place for now. */ 2715 fd = -1; 2716 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) 2717 fd = p[1]; 2718 else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) 2719 fd = devnull; 2720 if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { 2721 error("%s: dup2: %s", tag, strerror(errno)); 2722 _exit(1); 2723 } 2724 closefrom(STDERR_FILENO + 1); 2725 2726 if (geteuid() == 0 && 2727 initgroups(pw->pw_name, pw->pw_gid) == -1) { 2728 error("%s: initgroups(%s, %u): %s", tag, 2729 pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); 2730 _exit(1); 2731 } 2732 if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { 2733 error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, 2734 strerror(errno)); 2735 _exit(1); 2736 } 2737 if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { 2738 error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, 2739 strerror(errno)); 2740 _exit(1); 2741 } 2742 /* stdin is pointed to /dev/null at this point */ 2743 if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && 2744 dup2(STDIN_FILENO, STDERR_FILENO) == -1) { 2745 error("%s: dup2: %s", tag, strerror(errno)); 2746 _exit(1); 2747 } 2748 if (env != NULL) 2749 execve(av[0], av, env); 2750 else 2751 execv(av[0], av); 2752 error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", 2753 command, strerror(errno)); 2754 _exit(127); 2755 default: /* parent */ 2756 break; 2757 } 2758 2759 close(p[1]); 2760 if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) 2761 close(p[0]); 2762 else if ((f = fdopen(p[0], "r")) == NULL) { 2763 error("%s: fdopen: %s", tag, strerror(errno)); 2764 close(p[0]); 2765 /* Don't leave zombie child */ 2766 kill(pid, SIGTERM); 2767 while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) 2768 ; 2769 return 0; 2770 } 2771 /* Success */ 2772 debug3_f("%s pid %ld", tag, (long)pid); 2773 if (child != NULL) 2774 *child = f; 2775 return pid; 2776 } 2777 2778 const char * 2779 lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) 2780 { 2781 size_t i, envlen; 2782 2783 envlen = strlen(env); 2784 for (i = 0; i < nenvs; i++) { 2785 if (strncmp(envs[i], env, envlen) == 0 && 2786 envs[i][envlen] == '=') { 2787 return envs[i] + envlen + 1; 2788 } 2789 } 2790 return NULL; 2791 } 2792 2793 const char * 2794 lookup_setenv_in_list(const char *env, char * const *envs, size_t nenvs) 2795 { 2796 char *name, *cp; 2797 const char *ret; 2798 2799 name = xstrdup(env); 2800 if ((cp = strchr(name, '=')) == NULL) { 2801 free(name); 2802 return NULL; /* not env=val */ 2803 } 2804 *cp = '\0'; 2805 ret = lookup_env_in_list(name, envs, nenvs); 2806 free(name); 2807 return ret; 2808 } 2809 2810 /* 2811 * Helpers for managing poll(2)/ppoll(2) timeouts 2812 * Will remember the earliest deadline and return it for use in poll/ppoll. 2813 */ 2814 2815 /* Initialise a poll/ppoll timeout with an indefinite deadline */ 2816 void 2817 ptimeout_init(struct timespec *pt) 2818 { 2819 /* 2820 * Deliberately invalid for ppoll(2). 2821 * Will be converted to NULL in ptimeout_get_tspec() later. 2822 */ 2823 pt->tv_sec = -1; 2824 pt->tv_nsec = 0; 2825 } 2826 2827 /* Specify a poll/ppoll deadline of at most 'sec' seconds */ 2828 void 2829 ptimeout_deadline_sec(struct timespec *pt, long sec) 2830 { 2831 if (pt->tv_sec == -1 || pt->tv_sec >= sec) { 2832 pt->tv_sec = sec; 2833 pt->tv_nsec = 0; 2834 } 2835 } 2836 2837 /* Specify a poll/ppoll deadline of at most 'p' (timespec) */ 2838 static void 2839 ptimeout_deadline_tsp(struct timespec *pt, struct timespec *p) 2840 { 2841 if (pt->tv_sec == -1 || timespeccmp(pt, p, >=)) 2842 *pt = *p; 2843 } 2844 2845 /* Specify a poll/ppoll deadline of at most 'ms' milliseconds */ 2846 void 2847 ptimeout_deadline_ms(struct timespec *pt, long ms) 2848 { 2849 struct timespec p; 2850 2851 p.tv_sec = ms / 1000; 2852 p.tv_nsec = (ms % 1000) * 1000000; 2853 ptimeout_deadline_tsp(pt, &p); 2854 } 2855 2856 /* Specify a poll/ppoll deadline at wall clock monotime 'when' (timespec) */ 2857 void 2858 ptimeout_deadline_monotime_tsp(struct timespec *pt, struct timespec *when) 2859 { 2860 struct timespec now, t; 2861 2862 monotime_ts(&now); 2863 2864 if (timespeccmp(&now, when, >=)) { 2865 /* 'when' is now or in the past. Timeout ASAP */ 2866 pt->tv_sec = 0; 2867 pt->tv_nsec = 0; 2868 } else { 2869 timespecsub(when, &now, &t); 2870 ptimeout_deadline_tsp(pt, &t); 2871 } 2872 } 2873 2874 /* Specify a poll/ppoll deadline at wall clock monotime 'when' */ 2875 void 2876 ptimeout_deadline_monotime(struct timespec *pt, time_t when) 2877 { 2878 struct timespec t; 2879 2880 t.tv_sec = when; 2881 t.tv_nsec = 0; 2882 ptimeout_deadline_monotime_tsp(pt, &t); 2883 } 2884 2885 /* Get a poll(2) timeout value in milliseconds */ 2886 int 2887 ptimeout_get_ms(struct timespec *pt) 2888 { 2889 if (pt->tv_sec == -1) 2890 return -1; 2891 if (pt->tv_sec >= (INT_MAX - (pt->tv_nsec / 1000000)) / 1000) 2892 return INT_MAX; 2893 return (pt->tv_sec * 1000) + (pt->tv_nsec / 1000000); 2894 } 2895 2896 /* Get a ppoll(2) timeout value as a timespec pointer */ 2897 struct timespec * 2898 ptimeout_get_tsp(struct timespec *pt) 2899 { 2900 return pt->tv_sec == -1 ? NULL : pt; 2901 } 2902 2903 /* Returns non-zero if a timeout has been set (i.e. is not indefinite) */ 2904 int 2905 ptimeout_isset(struct timespec *pt) 2906 { 2907 return pt->tv_sec != -1; 2908 } 2909 2910 /* 2911 * Returns zero if the library at 'path' contains symbol 's', nonzero 2912 * otherwise. 2913 */ 2914 int 2915 lib_contains_symbol(const char *path, const char *s) 2916 { 2917 struct nlist nl[2]; 2918 int ret = -1, r; 2919 2920 memset(nl, 0, sizeof(nl)); 2921 nl[0].n_name = xstrdup(s); 2922 nl[1].n_name = NULL; 2923 if ((r = nlist(path, nl)) == -1) { 2924 error_f("nlist failed for %s", path); 2925 goto out; 2926 } 2927 if (r != 0 || nl[0].n_value == 0 || nl[0].n_type == 0) { 2928 error_f("library %s does not contain symbol %s", path, s); 2929 goto out; 2930 } 2931 /* success */ 2932 ret = 0; 2933 out: 2934 free(nl[0].n_name); 2935 return ret; 2936 } 2937